Foster’s flop, n. — Green’s Dictionary of Slang

Foster’s flop n.

[Foster’s lager, orig. brewed in Victoria, brought to UK popularity as the fictional ocker ‘Barry McKenzie’s’ drink of choice]

(Aus.) alcohol-induced impotence.

1988		L. Johansen Dink Dict. 137/2: Foster’s flop inability to achieve an erection of the penis due to excessive indulgence of alcohol.
1998		Tharunka (Kensington, NSW) 15 Sept. 18/4: It shall address important topics such as beer consumption, Foster's flop, how to pull chicks and most importantly, cars.